Extracting parts of a fraction in Excel 2

[rharr]

Hello.

I use Excel a lot for metric conversions as I draw in both inch and metric in AutoCAD. The problem with AutoCAD comes with using fractions - AutoCAD doesn't like fractions with decimals.
Because of this, I use 5/127 or 127/5 for metric conversion instead of 25.4.

How can I get Excel to extract the denominator of a fraction for a multiplier?
If the answer to a formula is 74.4mm, I'll use 372/127 to draw in inches. That's easy. Multiply 74.4 by 5/127.
If the answer is 204.75, it isn't so easy. I need to multiply by 4 first to remove the decimal portion.
By putting the answer in fraction form, 204.75 becomes 819/4. Now I want to pull the 4 out and use it as an additional multiplier with 5/127.

Can this be done? Can anyone suggest a work around?

 

[satchmo]

Full scale is full scale, no matter what system you are using to measure. You can offset as you said; when CAD prompts for an offset distance, type in 15/254. You can set the aperture size on your cusor if that is a problem. If you are not sure of the length of a line you have drawn, dimension with dual units on, and use the grips to stretch the line to the dimension you want. I always use snap to keep from having to force or round dimensions.